Method for collision management of a wireless detection system
First Claim
1. A method for managing collisions in a wireless detection system, said system comprising a plurality of receivers having a sending receiving module and at least one sending receiving unit for intermittent communication, via an on off switching cycle within a cycle, with said receivers located in a detection zone, comprising the steps of:
- transmitting a broadcast message from said sending receiving unit to at least one receiver and transmitting a quittance message to said sending receiving unit from a quittance device associated with said detection zone;
transmitting a presence message identifying said at least one receiver to said sending receiving unit, said message being transmitted by said at least one receiver upon receipt of said broadcast message, said message being transmitted after a time determined by a random generator;
transmitting an acknowledgement message from said sending receiving unit to said at least one receiver, said acknowledgement message acknowledging receipt of said presence message; and
if a collision occurs in the communication between said at least one receiver and said sending receiving unit, said collision is eliminated by;
repeating said step of transmitting a broadcast message if said quittance message is not received by said at least one receiver within a select cycle; and
repeating said step of transmitting a presence message, at a random time generated by a random generator, if said acknowledgement message is not received by said at least one receiver within a latency time after said step of transmitting a presence message.
2 Assignments
0 Petitions
Accused Products
Abstract
The invention relates to a method for managing collisions in a wireless detection system, wherein a plurality of portable receivers and at least one transmitter/receiver unit mounted on a vehicle are provided. Communication is of the intermittent type due to an on/off cycle. Sent call messages are first confirmed by a quittance device associated with the detection zone by means of a quittance report. The receivers respond to a received call message with an availability message that identifies the respective receiver. Before a message is sent, it is checked whether the radio medium is available. Collisions that occur are recognized by the absence of the quittance report. Communication is resumed by sending further messages at fixed intervals or at intervals that are determined by a random number generator. The inventive method provides for a complete detection of the portable receivers even when the ranges of detection overlap. The on/off cycle can be adaptively adjusted.
9 Citations
20 Claims
-
1. A method for managing collisions in a wireless detection system, said system comprising a plurality of receivers having a sending receiving module and at least one sending receiving unit for intermittent communication, via an on off switching cycle within a cycle, with said receivers located in a detection zone, comprising the steps of:
-
transmitting a broadcast message from said sending receiving unit to at least one receiver and transmitting a quittance message to said sending receiving unit from a quittance device associated with said detection zone;
transmitting a presence message identifying said at least one receiver to said sending receiving unit, said message being transmitted by said at least one receiver upon receipt of said broadcast message, said message being transmitted after a time determined by a random generator;
transmitting an acknowledgement message from said sending receiving unit to said at least one receiver, said acknowledgement message acknowledging receipt of said presence message; and
if a collision occurs in the communication between said at least one receiver and said sending receiving unit, said collision is eliminated by;
repeating said step of transmitting a broadcast message if said quittance message is not received by said at least one receiver within a select cycle; and
repeating said step of transmitting a presence message, at a random time generated by a random generator, if said acknowledgement message is not received by said at least one receiver within a latency time after said step of transmitting a presence message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification